This document discusses building modern data streaming apps with Python and provides an overview of Apache Pulsar. It introduces Tim Spann and his experience with streaming technologies. It then covers key Pulsar concepts like tenants, namespaces, topics and messages. It provides examples of building Python producers and consumers and integrating Pulsar with other technologies like Kafka, MQTT and websockets. It also demonstrates deploying Pulsar Functions with Python.

1. Building Modern Data
Streaming Apps with
Python
Tim Spann
Developer Advocate

2. 2
Tim Spann
Developer
Advocate
at StreamNative
FLiP(N) Stack = Flink, Pulsar and NiFi Stack
Streaming Systems & Data Architecture Expert
Experience:
● 15+ years of experience with streaming technologies
including Pulsar, Flink, Spark, NiFi, Big Data, Cloud, MXNet,
IoT, Python and more.
● Today, he helps to grow the Pulsar community sharing rich
technical knowledge and experience at both global
conferences and through individual conversations.

3. https://bit.ly/32dAJft
FLiP Stack Weekly
This week in Apache Flink, Apache
Pulsar, Apache NiFi, Apache Spark and
open source friends.

4. 4
Building
Real-Time
Requires a Team

5. Apache Pulsar has a vibrant community
560+
Contributors
10,000+
Commits
7,000+
Slack Members
1,000+
Organizations
Using Pulsar

6. Cloud native with decoupled
storage and compute layers.
Built-in compatibility with your
existing code and messaging
infrastructure.
Geographic redundancy and high
availability included.
Centralized cluster management
and oversight.
Elastic horizontal and vertical
scalability.
Seamless and instant partitioning
rebalancing with no downtime.
Flexible subscription model
supports a wide array of use cases.
Compatible with the tools you use
to store, analyze, and process data.
Pulsar Features

7. Messages - the basic unit of Pulsar
7
Component Description
Value / data payload The data carried by the message. All Pulsar messages contain raw bytes, although message data
can also conform to data schemas.
Key Messages are optionally tagged with keys, used in partitioning and also is useful for things like
topic compaction.
Properties An optional key/value map of user-defined properties.
Producer name The name of the producer who produces the message. If you do not specify a producer name, the
default name is used.
Sequence ID Each Pulsar message belongs to an ordered sequence on its topic. The sequence ID of the
message is its order in that sequence.

8. Integrated Schema Registry
Schema Registry
schema-1 (value=Avro/Protobuf/JSON) schema-2
(value=Avro/Protobuf/JSON)
schema-3
(value=Avro/Protobuf/JSON)
Schema
Data
ID
Local Cache
for Schemas
+
Schema
Data
ID +
Local Cache
for Schemas
Send schema-1
(value=Avro/Protobuf/JSON) data
serialized per schema ID
Send (register)
schema (if not in
local cache)
Read schema-1
(value=Avro/Protobuf/JSON) data
deserialized per schema ID
Get schema by ID (if
not in local cache)
Producers Consumers
8

9. DevOps: Pulsar Shell
https://pulsar.apache.org/docs/next/administration-pulsar-shell/
Welcome to Pulsar shell!
Service URL: pulsar://localhost:6650/
Admin URL: http://localhost:8080/
Type help to get started or try the autocompletion (TAB button).
Type exit or quit to end the shell session.
default(localhost)>
9

10. The FliPN kitten crosses the stream
4 ways with Apache Pulsar
10

11. Kafka on Pulsar (KoP)
11

12. Data Offloaders
(Tiered Storage)
Client Libraries
StreamNative Pulsar ecosystem
hub.streamnative.io
Connectors
(Sources & Sinks)
Protocol Handlers
Pulsar Functions
(Lightweight Stream
Processing)
Processing Engines
… and more!
… and more!

13. 13
Pulsar Functions
● Consume messages from one or
more Pulsar topics.
● Apply user-supplied processing
logic to each message.
● Publish the results of the
computation to another topic.
● Support multiple programming
languages (Java, Python, Go)
● Can leverage 3rd-party libraries to
support the execution of ML
models on the edge.

14. from pulsar import Function
from vaderSentiment.vaderSentiment import SentimentIntensityAnalyzer
import json
class Chat(Function):
def __init__(self):
pass
def process(self, input, context):
fields = json.loads(input)
sid = SentimentIntensityAnalyzer()
ss = sid.polarity_scores(fields["comment"])
row = { }
row['id'] = str(msg_id)
if ss['compound'] < 0.00:
row['sentiment'] = 'Negative'
else:
row['sentiment'] = 'Positive'
row['comment'] = str(fields["comment"])
json_string = json.dumps(row)
return json_string
Entire Function
ML Function
14

15. Starting a Function - Distributed Cluster
Once compiled into a JAR, start a Pulsar Function in a distributed cluster:
15

16. Building Tenant, Namespace, Topics
bin/pulsar-admin tenants create meetup
bin/pulsar-admin namespaces create meetup/newjersey
bin/pulsar-admin tenants list
bin/pulsar-admin namespaces list meetup
bin/pulsar-admin topics create persistent://meetup/newjersey/first
bin/pulsar-admin topics list meetup/newjersey
16

17. Install Python 3 Pulsar Client
pip3 install pulsar-client=='2.9.1[all]'
# Depending on Platform May Need C++ Client Built
For Python on Pulsar on Pi https://github.com/tspannhw/PulsarOnRaspberryPi
https://pulsar.apache.org/docs/en/client-libraries-python/

18. Building a Python3 Producer
import pulsar
client = pulsar.Client('pulsar://localhost:6650')
producer
client.create_producer('persistent://conf/ete/first')
producer.send(('Simple Text Message').encode('utf-8'))
client.close()

19. python3 prod.py -su pulsar+ssl://name1.name2.snio.cloud:6651 -t
persistent://public/default/pyth --auth-params
'{"issuer_url":"https://auth.streamnative.cloud", "private_key":"my.json",
"audience":"urn:sn:pulsar:name:myclustr"}'
from pulsar import Client, AuthenticationOauth2
parse = argparse.ArgumentParser(prog=prod.py')
parse.add_argument('-su', '--service-url', dest='service_url', type=str,
required=True)
args = parse.parse_args()
client = pulsar.Client(args.service_url,
authentication=AuthenticationOauth2(args.auth_params))
https://github.com/streamnative/examples/blob/master/cloud/python/OAuth2Producer.py
https://github.com/tspannhw/FLiP-Pi-BreakoutGarden
Producer with OAuth to Cloud

20. import pulsar
from pulsar.schema import *
from pulsar.schema import AvroSchema
class thermal(Record):
uuid = String()
client = pulsar.Client('pulsar://pulsar1:6650')
thermalschema = AvroSchema(thermal)
producer =
client.create_producer(topic='persistent://public/default/pi-thermal-avro',
schema=thermalschema,properties={"producer-name": "thrm" })
thermalRec = thermal()
thermalRec.uuid = "unique-name"
producer.send(thermalRec,partition_key=uniqueid)
https://github.com/tspannhw/FLiP-Pi-Thermal
Example Avro Schema Usage

21. import pulsar
from pulsar.schema import *
from pulsar.schema import JsonSchema
class weather(Record):
uuid = String()
client = pulsar.Client('pulsar://pulsar1:6650')
wsc = JsonSchema(thermal)
producer =
client.create_producer(topic='persistent://public/default/wthr,schema=wsc,pro
perties={"producer-name": "wthr" })
weatherRec = weather()
weatherRec.uuid = "unique-name"
producer.send(weatherRec,partition_key=uniqueid)
https://github.com/tspannhw/FLiP-Pi-Weather
https://github.com/tspannhw/FLiP-PulsarDevPython101
Example JSON Schema Usage

22. import pulsar
client = pulsar.Client('pulsar://localhost:6650')
consumer =
client.subscribe('persistent://conf/ete/first',subscription_name='mine')
while True:
msg = consumer.receive()
print("Received message: '%s'" % msg.data())
consumer.acknowledge(msg)
client.close()
Building a Python Producer

23. pip3 install paho-mqtt
import paho.mqtt.client as mqtt
client = mqtt.Client("rpi4-iot")
row = { }
row['gasKO'] = str(readings)
json_string = json.dumps(row)
json_string = json_string.strip()
client.connect("pulsar-server.com", 1883, 180)
client.publish("persistent://public/default/mqtt-2",
payload=json_string,qos=0,retain=True)
https://www.slideshare.net/bunkertor/data-minutes-2-apache-pulsar-with-mqtt-for-edge-computing-lightning-2022
Sending MQTT Messages

24. pip3 install websocket-client
import websocket, base64, json
topic = 'ws://server:8080/ws/v2/producer/persistent/public/default/topic1'
ws = websocket.create_connection(topic)
message = "Hello Philly ETE Conference"
message_bytes = message.encode('ascii')
base64_bytes = base64.b64encode(message_bytes)
base64_message = base64_bytes.decode('ascii')
ws.send(json.dumps({'payload' : base64_message,'properties': {'device' :
'macbook'},'context' : 5}))
response = json.loads(ws.recv())
https://pulsar.apache.org/docs/en/client-libraries-websocket/
https://github.com/tspannhw/FLiP-IoT/blob/main/wspulsar.py
https://github.com/tspannhw/FLiP-IoT/blob/main/wsreader.py
Sending Websocket Messages

25. pip3 install kafka-python
from kafka import KafkaProducer
from kafka.errors import KafkaError
row = { }
row['gasKO'] = str(readings)
json_string = json.dumps(row)
json_string = json_string.strip()
producer = KafkaProducer(bootstrap_servers='pulsar1:9092',retries=3)
producer.send('topic-kafka-1', json.dumps(row).encode('utf-8'))
producer.flush()
https://github.com/streamnative/kop
https://docs.streamnative.io/platform/v1.0.0/concepts/kop-concepts
Sending Kafka Messages

26. bin/pulsar-admin functions create --auto-ack true --py py/src/sentiment.py
--classname "sentiment.Chat" --inputs "persistent://public/default/chat"
--log-topic "persistent://public/default/logs" --name Chat --output
"persistent://public/default/chatresult"
https://github.com/tspannhw/pulsar-pychat-function
DevOps: Deploying Functions

27. 27
Apache
Pulsar
in Action

28. @PassDev
https://www.linkedin.com/in/timothyspann
https://github.com/tspannhw
https://streamnative.io/pulsar-python/
28
Tim Spann
Developer Advocate
at StreamNative